10+ Technical Dotnet Lead Interview Questions and Answers

Exception handling and filters in .NET Core Web API

• Use try-catch blocks to handle exceptions in the code

• Implement global exception handling middleware to catch unhandled exceptions

• Use filters like [Authorize] for authentication and [ValidateAntiForgeryToken] for CSRF protection

• Create custom exception filters by implementing IExceptionFilter interface

I have used the asynchronous messaging pattern for Microservice communication.

• Implemented messaging queues like RabbitMQ or Kafka for decoupled communication

• Used message brokers to enable communication between Microservices

• Leveraged event-driven architecture for real-time updates and scalability

We are using OAuth 2.0 for single sign on in the project.

• OAuth 2.0 is a widely used authorization framework that enables a third-party application to obtain limited access to an HTTP service.

• It allows users to log in once and access multiple applications without having to log in again.

• OAuth 2.0 provides secure delegated access to resources without sharing user credentials.

I have used Application Insights for monitoring and analyzing the performance of .NET applications.

• Used Application Insights to track application performance metrics

• Analyzed telemetry data to identify performance bottlenecks

• Set up alerts and notifications for critical issues

• Integrated Application Insights with Azure DevOps for continuous monitoring

We use in-memory caching technique in our project to improve performance and reduce database load.

• In-memory caching is used to store frequently accessed data in memory for quick retrieval

• Helps reduce database load and improve application performance

• Examples: using MemoryCache in .NET, Redis caching, caching frequently accessed data like user profiles or product information

Yes, API Gateways are used in Microservices to manage and secure communication between services.

• API Gateways act as a single entry point for clients to access multiple microservices

• They handle authentication, authorization, rate limiting, logging, and monitoring

• Examples of API Gateways include Kong, Apigee, and AWS API Gateway

Authentication using application involves verifying the identity of users before granting access to resources.

• Use authentication mechanisms like username/password, tokens, or biometrics.

• Implement secure protocols like OAuth or OpenID Connect.

• Utilize multi-factor authentication for added security.

• Regularly update authentication methods to stay ahead of security threats.

Delegates are type-safe function pointers in C# that allow methods to be passed as parameters.

• Delegates are similar to function pointers in C/C++.

• Delegates can be used to define callback methods.

• Delegates can be used to implement events in C#.

• Delegates are type-safe and secure.

• Example: delegate void MyDelegate(string message);

OOPs is a programming paradigm based on the concept of objects, which can contain data and code.

• OOPs stands for Object-Oriented Programming.

• It focuses on creating objects that interact with each other to solve a problem.

• Encapsulation, Inheritance, Polymorphism, and Abstraction are the four main pillars of OOPs.

• Example: A car can be considered as an object that has properties like color, model, and features, and methods like start, stop, and accelerate.

• OOPs makes code reusable...read more

SOLID principles are a set of five design principles for writing maintainable and scalable code.

• Single Responsibility Principle (SRP) - a class should have only one reason to change

• Open/Closed Principle (OCP) - software entities should be open for extension but closed for modification

• Liskov Substitution Principle (LSP) - objects of a superclass should be able to be replaced with objects of a subclass without breaking the program

• Interface Segregation Principle (ISP) - clients ...read more